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                            <div style="color:gray; word-break: break-all; font-size:12px;">原英文版地址: <a href="https://www.elastic.co/guide/en/elasticsearch/reference/7.7/analysis-condition-tokenfilter.html" rel="nofollow" target="_blank">https://www.elastic.co/guide/en/elasticsearch/reference/7.7/analysis-condition-tokenfilter.html</a>, 原文档版权归 www.elastic.co 所有<br/>本地英文版地址: <a href="../en/analysis-condition-tokenfilter.html" rel="nofollow" target="_blank">../en/analysis-condition-tokenfilter.html</a></div>
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<span class="breadcrumb-node">Conditional token filter</span>
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<h2 class="title">
<a id="analysis-condition-tokenfilter"></a>Conditional token filter<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/analysis/tokenfilters/condition-tokenfilter.asciidoc">edit</a>
</h2>
</div></div></div>

<p>Applies a set of token filters to tokens that match conditions in a provided
predicate script.</p>
<p>This filter uses Lucene’s
<a href="https://lucene.apache.org/core/8_5_1/analyzers-common/org/apache/lucene/analysis/miscellaneous/ConditionalTokenFilter.html" class="ulink" target="_top">ConditionalTokenFilter</a>.</p>
<div class="section">
<div class="titlepage"><div><div>
<h3 class="title">
<a id="analysis-condition-analyze-ex"></a>Example<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/analysis/tokenfilters/condition-tokenfilter.asciidoc">edit</a>
</h3>
</div></div></div>
<p>The following <a class="xref" href="indices-analyze.html" title="Analyze API">analyze API</a> request uses the <code class="literal">condition</code>
filter to match tokens with fewer than 5 characters in <code class="literal">THE QUICK BROWN FOX</code>.
It then applies the <a class="xref" href="analysis-lowercase-tokenfilter.html" title="Lowercase token filter"><code class="literal">lowercase</code></a> filter to
those matching tokens, converting them to lowercase.</p>
<div class="pre_wrapper lang-console">
<pre class="programlisting prettyprint lang-console">GET /_analyze
{
  "tokenizer": "standard",
  "filter": [
    {
      "type": "condition",
      "filter": [ "lowercase" ],
      "script": {
        "source": "token.getTerm().length() &lt; 5"
      }
    }
  ],
  "text": "THE QUICK BROWN FOX"
}</pre>
</div>
<div class="console_widget" data-snippet="snippets/907.console"></div>
<p>The filter produces the following tokens:</p>
<div class="pre_wrapper lang-text">
<pre class="programlisting prettyprint lang-text">[ the, QUICK, BROWN, fox ]</pre>
</div>
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<div class="titlepage"><div><div>
<h3 class="title">
<a id="analysis-condition-tokenfilter-configure-parms"></a>Configurable parameters<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/analysis/tokenfilters/condition-tokenfilter.asciidoc">edit</a>
</h3>
</div></div></div>
<div class="variablelist">
<dl class="variablelist">
<dt>
<span class="term">
<code class="literal">filter</code>
</span>
</dt>
<dd>
<p>(Required, array of token filters)
Array of token filters. If a token matches the predicate script in the <code class="literal">script</code>
parameter, these filters are applied to the token in the order provided.</p>
<p>These filters can include custom token filters defined in the index mapping.</p>
</dd>
<dt>
<span class="term">
<code class="literal">script</code>
</span>
</dt>
<dd>
<p>(Required, <a class="xref" href="modules-scripting-using.html" title="How to use scripts">script object</a>)
Predicate script used to apply token filters. If a token
matches this script, the filters in the <code class="literal">filter</code> parameter are applied to the
token.</p>
<p>For valid parameters, see <a class="xref" href="modules-scripting-using.html#_script_parameters" title="Script parameters">Script parameters</a>. Only inline scripts are
supported. Painless scripts are executed in the
<a href="https://www.elastic.co/guide/en/elasticsearch/painless/7.7/painless-analysis-predicate-context.html" class="ulink" target="_top">analysis predicate context</a>
and require a <code class="literal">token</code> property.</p>
</dd>
</dl>
</div>
</div>

<div class="section">
<div class="titlepage"><div><div>
<h3 class="title">
<a id="analysis-condition-tokenfilter-customize"></a>Customize and add to an analyzer<a class="edit_me edit_me_private" rel="nofollow" title="Editing on GitHub is available to Elastic" href="https://github.com/elastic/elasticsearch/edit/7.7/docs/reference/analysis/tokenfilters/condition-tokenfilter.asciidoc">edit</a>
</h3>
</div></div></div>
<p>To customize the <code class="literal">condition</code> filter, duplicate it to create the basis
for a new custom token filter. You can modify the filter using its configurable
parameters.</p>
<p>For example, the following <a class="xref" href="indices-create-index.html" title="Create index API">create index API</a> request
uses a custom <code class="literal">condition</code> filter to configure a new
<a class="xref" href="analysis-custom-analyzer.html" title="Create a custom analyzer">custom analyzer</a>. The custom <code class="literal">condition</code> filter
matches the first token in a stream. It then reverses that matching token using
the <a class="xref" href="analysis-reverse-tokenfilter.html" title="Reverse token filter"><code class="literal">reverse</code></a> filter.</p>
<div class="pre_wrapper lang-console">
<pre class="programlisting prettyprint lang-console">PUT /palindrome_list
{
  "settings": {
    "analysis": {
      "analyzer": {
        "whitespace_reverse_first_token": {
          "tokenizer": "whitespace",
          "filter": [ "reverse_first_token" ]
        }
      },
      "filter": {
        "reverse_first_token": {
          "type": "condition",
          "filter": [ "reverse" ],
          "script": {
            "source": "token.getPosition() === 0"
          }
        }
      }
    }
  }
}</pre>
</div>
<div class="console_widget" data-snippet="snippets/908.console"></div>
</div>

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